High school students' body weight control: differences between athletes and non-athletes

Due to chronic dissatisfaction with body weight in youth, efforts to lose weight often lead to pathological dietary behaviours. Regular and heavy sports activity may contribute to the optimization of body weight, not only by elevating the energy utilization but also by increasing the health consciousness and the tendency to self-monitor. Research generally finds a beneficial role of extracurricular sports activity in body weight control. Therefore, we aim to analyze how regular, heavy sports activity (more precisely, competitive sports) may contribute to body weight control among two groups of youth: athletes and non-athletes. Our study was carried out using 347 adolescents; among them there were 91 athletes and 259 controls. The subjects completed self-administered questionnaires concerning their body weight control and dietary habits. We found that girls were less satisfied with their body weight and reported dieting more frequently with a greater emphasis on healthy dieting than boys. Sport influenced these strong gender differences only regarding healthy dieting, young male athletes laid a larger emphasis on healthy diets than their non-athlete counterparts, therefore their attitude became similar to that of female athletes and non-athletes. We conclude that despite the normal weight in high school students, episodes of dieting that might contribute to eating disorders were quite frequent. This was not influenced by the students' extracurricular sports activity. A greater monitoring of male athletes' and their friend's diet draw attention to the need for developing health education programs specific to boys.     

Influences of weight loss on monocytes and T-cell subpopulations in male judo athletes

The purpose of this study was to examine weight loss effects on immune function in judo athletes. Six elite male Japanese judo athletes (20.3 ± 0.4 years) were enrolled in this study. They completed usual weight loss programs during 2 weeks preceding an actual competition. Subjects noted the appearance of upper-respiratory tract infection (URTI) symptoms during the study period. Blood samples were obtained at 40 (baseline period: BL) and 3 (weight loss period: WL) days before and 1 day after the competition (AC). The CD3, CD4, CD8, CD56CD3, CD28CD4, CD28CD8, and Toll-like-receptor-4 (TLR-4) CD14 cells were counted by using flow cytometer analysis. The 6 subjects reported 1 headache, 3 runny nose conditions, and 1 coughing instance during the WL. The CD3, CD4, CD8, and CD28CD4 cell counts were significantly lower at WL than at BL (p ≤ 0.05); they reverted to the baseline value at AC. The TLR-4CD14 cells were significantly fewer at WL (p ≤ 0.05); they remained fewer than they had been at BL, even at AC. These results suggest that 2 weeks of weight loss before a competition can impair cell-mediated immune function and induce high susceptibility to URTI in judo athletes. Coaches, support staff, and athletes should monitor athletes' weight loss, hydration status, appearance of URTI symptoms, and immunocompetence such as lymphocytes and monocytes to prevent the physical condition from becoming worse.     

A prospective analysis of patients undergoing silicone breast implant explantation

Despite the lack of a scientifically proven link between silicone implants and disease, many women have chosen to have their implants removed out of concern for their health. Unfortunately, there are few studies in the literature that have investigated the outcome of explanations, and there are no prospective analyses of the effect explantation has on a patient's general health. The goal of this study was to use a prospective database to determine whether there were any preoperative parameters that could be used to predict which patients would be improved following removal of silicone breast implants and to provide a quantifiable measure of that improvement. A total of 38 patients with silicone breast implants underwent operative removal of their breast implants by faculty at the University of Texas Southwestern Medical Center. They were given questionnaires regarding several personal and medical parameters to be completed preoperatively, at 6 weeks postoperatively, and at 6 months postoperatively. In addition, their physicians completed preoperative and postoperative evaluations of the patient's general health status. A control group of 38 patients was established; they were matched with the experimental group with regard to age and other initial parameters. Their responses to questionnaires were then grouped according to standard subscales to evaluate physical functioning, physical role, bodily pain, general health, vitality, social functioning, emotional role, mental health, appearance evaluation, appearance orientation, illness orientation, and body area satisfaction. When compared with the control group, we found that patients who had undergone explantation showed a temporary decrease in musculoskeletal symptoms and bodily pain, as well as an increase in vitality, mental health, and body area satisfaction. Of the experimental group, those who initially indicated a higher number of musculoskeletal symptoms and a higher appearance evaluation were more likely to indicate a significant improvement in general health since explantation.     

Perceived social support from strength and conditioning coaches among injured student athletes

Injuries suffered by student athletes not only affect their physical ability to perform in sport but also have psychological effects as well. The purpose of this study was to examine student athletes' perceptions, expectations, and satisfaction of the social support provided by their strength and conditioning coach (SC) during the later reconditioning stage of their rehabilitation and their views on the overall level of importance of each type of social support. One hundred and sixty-five participants aged 20.21 ± 1.32 years from 6 Division I Universities in the Midwest region of the USA completed the modified Social Support Survey. The results of a chi-square test assessing the responses for 6 types of social support provided by SCs based on athletes' age, gender, and sport revealed a significant difference (χ2[13,105] = 26.46, p = 0.015) for listening support differing by sport. A significant difference (χ2[13,105] = 267.74, p = 0.010) was also revealed for reported emotional challenge by sport. Results showed that the SC had a significant psychosocial impact on student-athletes' overall psychological well-being during reconditioning. This study provides evidence of the vital psychosocial role that SCs can play during an injured student-athlete's reconditioning program.     

Determination of the energy load of erythrocytes in long-distance and medium-distance runners

In this study erythrocytes drawn from well-trained athletes (middle- and long-distance runners) and from sedentary subjects have been compared for their adenine nucleotide contents. ADP and AMP appeared to be significantly (p less than 0,001) increased only in red cells from athletes in the rest state. After athletes' race this difference with control subjects become insignificant. Nevertheless, the observed ADP and AMP modifications are not great enough to influence the energy charge (CE) of the compared erythrocytes.     

Biochemical and heart adaptations to physical training and supplementation with amino acids

This study evaluated the role of amino acids supplementation on the heart's adaptation under extensive training conditions. Sixty active athletes (bicyclists and swimmers) were separated into 2 groups: 30 were given amino acid mixture (1 g per 10 kg of body weight) for a period of 1 month, and the other 30 were given placebo for the same duration (control group). In the same time period, 20 subjects of similar age not engaged in physical training or sports activities were used as the additional control group. Blood concentrations of alanine transaminase (ALT), asparagine transaminase, lactate dehydrogenase (LDH), gamma-glutamil transpeptidase, alkaline phosphatase (ALP), amylase, triglycerides, albumin, interleukin-6 (IL-6), and interleukin-10 (IL-10) were determined for all subjects before and after the intervention period. Concentrations of LDH and ALP were increased, but concentrations of ALT, albumin, and triglycerides were decreased in the blood of trained athletes compared with healthy subjects not engaged in sports activities. In the athletes, some increases in IL-6 levels were noted; however, they were significantly (p < 0.05) lower than in patients with myocardiodystrophy. The values of IL-10 in athletes were higher than concentrations of IL-10 in patients with myocardiodystrophy but still lower than the normal values. The inhibition of IL-10 in blood may play an important role in the induction of apoptosis in cells of the heart muscle. After amino acid supplementation, the athletes' values for albumin, triglycerides, IL-10, LDH, and ALP were significantly increased compared with the post-placebo control groups. Enzyme activities of other enzymes remained unchanged in all groups. Histological data from a secondary study of actual heart tissue showed that the amino acids supplementation may have inhibiting effects on myocardial apoptosis. The criteria of efficiency of the amino acids supplementation were defined by the albumin, IL-6, and IL-10 concentrations.     

Histochemical and enzymatic characteristics of skeletal muscle in master athletes

Many older athletes are capable of endurance performances equal to those of young runners who have higher maximal O2 uptakes (VO2max). To determine whether this is a result of differences in skeletal muscle characteristics, gastrocnemius muscle biopsy samples were obtained from eight master athletes [aged 63 +/- 6 (SD) yr] and eight young (aged 26 +/- 3 yr) runners. The young runners were matched with the master athletes for 10-km running performance and for their volume, pace, and type of training. Despite similar 10-km run times, VO2max was 11% lower (P less than 0.05) in the master athletes. Fiber type distribution did not differ between groups, with both groups having 60% type I and very few type IIb fibers. Succinate dehydrogenase and beta-hydroxyacyl-CoA dehydrogenase activities, however, were 31 and 24% higher in the master athletes compared with the matched young runners, whereas lactate dehydrogenase activity was 46% lower (all P less than 0.05). The capillary-to-fiber ratio was also greater in the master athletes; however, capillary density was similar in the two groups, because of the master athletes' 34% larger (P less than 0.05) type I fibers. These differences in skeletal muscle characteristics may explain the master athletes' ability to perform as well as some young runners despite having a lower VO2max.     

Salivary IgA is not a reliable indicator of upper respiratory infection in collegiate female soccer athletes

It has been shown that mucosal immunity measures such as salivary immunoglobulin A (s-IgA) can be affected by sport activities and has resulted in an increased susceptibility to infection. However, there is limited research that has evaluated the change in s-IgA throughout a full sport training season. The purpose of the study was to evaluate the change in s-IgA levels and incidence of upper respiratory infection in the National Collegiate Athletic Association Division I level female soccer athletes compared to age matched controls over an entire sport training season. Saliva samples were collected from 12 randomly selected female collegiate soccer athletes and 8 age-matched controls. Samples were collected bimonthly from the athletes' pre-and post-sport training sessions and pre- and post-90-minute sedentary period for the controls. Analysis showed there was a significant (p < 0.05) group × time interaction in total protein (TP) for collections 1 and 4 and a significant (p < 0.05) group × time interaction in s-IgA/TP for collections 2 and 3. There was no significant difference (p > 0.05) between athletes and controls for s-IgA or total symptom days (TSDs). Furthermore, there was no significant correlation between absolute s-IgA and TSDs or s-IgA/TP and TSDs throughout the sport training season. The large range of measurable levels for s-IgA at the different time points for athletes and controls and the lack of relationship between s-IgA levels and TSDs indicate that s-IgA is not an appropriate measure to determine an athlete's susceptibility to during a training season.     

URINARY CREATINE AT REST AND AFTER REPEATED SPRINTS IN ATHLETES: A PILOT STUDY

Creatine plays a key role in muscle function and its evaluation is important in athletes. In this study, urinary creatine concentration was measured in order to highlight its possible significance in monitoring sprinters. The study included 51 sprinters and 25 age- and sex-matched untrained subjects as a control group. Body composition was measured and dietary intake estimated. Urine samples were collected before and after standardized physical exercise. Creatine was assessed by gas chromatography mass spectrometry. Basal urinary creatine (UC) was significantly lower in sprinters than controls (34±30 vs. 74±3 µmol/mmol creatinine, p < 0.05). UC was inversely correlated with body mass (r = −0.34, p < 0.01) and lean mass (r = −0.30, p < 0.05), and positively correlated with fat mass (r = 0.32, p < 0.05). After acute exercise, urinary creatine significantly decreased in both athletes and controls. UC is low in sprinters at rest and further decreases after exercise, most likely due to a high uptake and use of creatine by muscles, as muscle mass and physical activity are supposed to be greater in athletes than untrained subjects. Further studies are needed to test the value of urinary creatine as a non-invasive marker of physical condition and as a parameter for managing Cr supplementation in athletes.     

Acute effect of whole-body vibration on sprint and jumping performance in elite skeleton athletes

The winter sliding sport known as skeleton requires athletes to produce a maximal sprint followed by high speed sliding down a bobsled track. Athletes are required to complete the course twice in 1 hour and total time for the 2 runs determines overall ranking. The purpose of this investigation was to examine the effect of whole-body vibration (WBV) on lower body power to explore the utility of WBV as an ergogenic aid for skeleton competition. Elite skeleton athletes (1 male and 6 females) completed an unloaded squat jump (SQJ) immediately followed by 2 countermovement jumps (CMJs) and a maximal 30-m sprint before and after WBV or no vibration (CON) using a crossover design. The second 30-m sprint was slower following both CON (1.4% decrement; p = 0.05) and WBV (0.7% decrement; p = 0.03). Mean vertical velocity was maintained following WBV in the SQJ but decreased following CON (p = 0.03). There was a trend for athletes to commence the SQJ from a higher starting stance post-WBV compared to CON (p = 0.08). WBV decreased total vertical distance traveled compared to CON in the SQJ (p = 0.006). WBV had little effect on peak velocity, jump height, dip, and peak acceleration or any CMJ parameters. When sprint athletes' warm up and perform maximal jumps and a 30-m sprint with 15-20 minutes of recovery before repeating the sequence, the second series of performances tend to be compromised. However, when WBV is used before the second series of efforts, some aspects of maximal jumping and sprinting appear to be influenced in a beneficial manner. Further research is required to explore whether WBV can improve the second sprint for athletes in actual competition and/or what sort of WBV protocol is optimal for these populations.     

Nuclear p120 catenin is a component of the perichromosomal layer and coordinates sister chromatid segregation during mitosis in lung cancer cells

Abnormal expression of p120 catenin is associated with the malignant phenotype in human lung cancer. Numerous studies have focused on the function of p120 catenin in the juxta-membrane compartment. However, the role of nuclear p120 catenin remains unclear. In this study, the dynamic changes in nuclear p120 catenin localization during cell cycle progression were investigated. Immunofluorescent staining, FACS analysis, and western blotting revealed that nuclear p120 catenin is a major architectural constituent of the chromosome periphery during mitosis. During mitosis, granule-like p120 catenin dispersed into a cloudy-like structure and formed cordon-like structures surrounding the condensed chromosomes to create the peri-chromosomal layer. Interestingly, lumican and p120 catenin colocalized at the spindle fiber where the perichromosomal layer connects to the condensed chromosomes during mitosis. Furthermore, downregulation of p120 catenin using a specific siRNA induced cell cycle stalling in the G2/M phase and promoted aneuploidy. This study validates the role of nuclear p120 catenin in the formation of the chromosome periphery and reveals the p120 catenin-lumican interaction may couple orientation of cell division with the segregation of sister chromatids during mitosis. Our data suggest the protective role of p120 catenin in maintaining the integrity of chromosomes, and also warrants further studies to evaluate the contribution of the loss of p120 catenin to the creation of gene rearrangement in cancer evolution and tumor progression.Subject terms: Non-small-cell lung cancer, Cell biology     

Effects of conjugated linoleic acid supplementation during resistance training on body composition,bone density,strength, and selected hematological markers

Conjugated linoleic acids (CLA) are essential fatty acids that have been reported in animal studies to decrease catabolism, promote fat loss, increase bone density, enhance immunity, and serve as an antiatherogenic and anticarcinogenic agent. For this reason, CLA has been marketed as a supplement to promote weight loss and general health. CLA has also been heavily marketed to resistance-trained athletes as a supplement that may help lessen catabolism, decrease body fat, and promote greater gains in strength and muscle mass during training. Although basic research is promising, few studies have examined whether CLA supplementation during training enhances training adaptations and/or affects markers of health. This study evaluated whether CLA supplementation during resistance training affects body composition, strength, and/or general markers of catabolism and immunity. In a double-blind and randomized manner, 23 experienced, resistance-trained subjects were matched according to body mass and training volume and randomly assigned to supplement their diet with 9 g;pdd(-1) of an olive oil placebo or 6 g;pdd(-1) of CLA with 3 g;pdd(-1) of fatty acids for 28 days. Prior to and following supplementation, fasting blood samples, total body mass, and dual-energy X-ray absorptiometry (DEXA) determined body composition, and isotonic bench press and leg press 1 repetition maximums (1RMs) were determined. Results revealed that although some statistical trends were observed with moderate to large effect sizes, CLA supplementation did not significantly affect (p > 0.05) changes in total body mass, fat-free mass, fat mass, percent body fat, bone mass, strength, serum substrates, or general markers of catabolism and immunity during training. These findings indicate that CLA does not appear to possess significant ergogenic value for experienced resistance-trained athletes.     

Motor Control Organization and Features of Cerebral Functional Asymmetry in Wrestlers

Factor analysis of the motor profile parameters demonstrated that the so-called instrumental tests became a separate factor only in athletes, and the features of carrying out these tests correlated with the wrestlers' stances. Apart from this, different indices of the athletes' hand preference were divided into many factors. The data of dichotic and dichoptic tests showed that, firstly, the athletes demonstrated a preponderance of the right hemisphere in processing verbal and visual–spatial information; secondly, the wrestlers' athletic results correlated with the preponderance of the left hemisphere in speech perception. The controversial character of the data obtained is explained by the bilateral organization of motor control in wrestlers and the involvement of the regulatory mechanisms of the interhemispheric interaction.     

Body mass change and ultraendurance performance: a decrease in body mass is associated with an increased running speed in male 100-km ultramarathoners

We investigated, in 50 recreational male ultrarunners, the changes in body mass, selected hematological and urine parameters, and fluid intake during a 100-km ultramarathon. The athletes lost (mean and SD) 2.6 (1.8) % in body mass (p < 0.0001). Running speed was significantly and negatively related to the change in body mass (p < 0.05). Serum sodium concentration ([Na?]) and the concentration of aldosterone increased with increasing loss in body mass (p < 0.05). Urine-specific gravity increased (p < 0.0001). The change in body mass was significantly and negatively related to postrace serum [Na?] (p < 0.05). Fluid intake was significantly and positively related to both running speed (r = 0.33, p = 0.0182) and the change in body mass (r = 0.44, p = 0.0014) and significantly and negatively to both postrace serum [Na?] (r = -0.42, p = 0.0022) and the change in serum [Na?] (r = -0.38, p = 0.0072). This field study showed that recreational, male, 100-km ultramarathoners dehydrated as evidenced by the decrease in >2 % body mass and the increase in urine-specific gravity. Race performance, however, was not impaired because of the loss in body mass. In contrast, faster athletes lost more body mass compared with slower athletes while also drinking more. The concept that a loss of >2% in body mass leads to dehydration and consequently impairs endurance performance must be questioned for ultraendurance athletes competing in the field. For practical applications, a loss in body mass during a 100-km ultramarathon was associated with a faster running speed.     

Parenting style and cultural influences on overweight children's attraction to physical activity

Objective: To investigate the associations among parenting style, gender, Chinese culture, and overweight children's attraction to physical activity. Research Methods and Procedures: A total of 104 parents with overweight children were recruited from six primary schools in Hong Kong, China. Only overweight children in grades 3 through 6 (8 to 12 years of age) were invited to participate. Overweight children were defined and identified using the international cut‐off points stratified by sex and age. Questionnaires were used to assess Children's Attraction to Physical Activity (CAPA), perceived competence, and parental socialization influences. Results: Parental influence, especially father's role modeling, was significantly related to attraction to physical activity in overweight Chinese children. Perceived physical competence was also an important correlate of an overweight child's attraction to physical activity. Gender differences in CAPA were not significant among the Chinese overweight children. However, gender differences were observed in the relationship between parent physical activity orientation and CAPA. Discussion: In addition to a child's perceived competence, father's role modeling can provide additional and significant influence with regard to overweight children's attraction to physical activity. Differences in cultural orientation toward body weight should be considered when explaining overweight children's physical activity.     

Gender roles in persistent sex differences in health-related quality-of-life outcomes of patients with coronary artery disease

Background: The increased recognition of significant sex/gender differences in health status outcomes, and the implications for clinical practice and service delivery, has led to calls for more gender sensitivity and specificity in research endeavors as well as within clinical practice. Previous investigations by our research group have consistently identified important sex differences in both changes in health status from baseline to 1 year and in health status outcomes of patients treated for coronary artery disease (CAD), with women reporting poorer health-related quality of life (HRQoL) compared with men.Objective: The objective of this study was to examine whether persistent sex differences in the health status of patients with CAD may be attributed to social factors such as gender roles.Methods: Sex differences in baseline clinical and demographic characteristics of patients who completed the 1-year follow-up survey were examined using t tests and χ² analyses. Structural equation modeling, an inclusive statistical modeling approach for testing hypotheses about relationships among measured and latent variables (concepts not observed or measured directly), was used to test our theoretical model.Results: HRQoL data were collected on 2403 patients 1 year after index catheterization. The results indicated that the model fit was substantially improved by the addition of the conceptualized gender-role variable. Furthermore, there was a significant effect of gender role on QoL (?0.106; P < 0.05). Age, coronary anatomy, ejection fraction, physical limitation, anginal frequency, and gender role variables in this model were able to explain 51% of the variance in HRQoL. In particular, reported physical limitations, anginal frequency, and gender role had large statistically significant direct effects on HRQoL.Conclusions: Advances in the treatment of CAD have led to significant decreases in mortality rates. Our current challenge is to minimize the long-term impact of CAD on HRQoL outcomes. While a substantial body of literature has examined the correlations between gender-role attributes and a wide variety of both positive and negative outcomes, this area has not been explored in patients with cardiovascular disease. These findings suggest that further study of the influence of gender role (using a gender-role measurement) on HRQoL is needed.     

Tactile perception and manual dexterity in computer users

Recent studies suggest that sensory input generated during highly repetitive tasks can degrade the sensory representation of the hand and eventually lead to sensory and motor problems. In this study, we investigated whether early changes in tactile perception and manual dexterity could be detected in persons exposed to computer tasks. Performance in tests designed to assess tactile perception (grating orientation task for spatial acuity and roughness discrimination) and manual dexterity (grooved pegboard test) was compared between two groups of healthy individuals, matched for age, gender, and experience, who differed in terms of computer habits. One group consisted of frequent users (FU, > 2 h/day, n = 36) and the other of non or occasional users (OU, < 2 h/day, n = 28). Comparison of performance between groups with subjects sorted by gender revealed significant differences (t-test, p < 0.05) in female, but not male, participants. Grating resolution thresholds at the tip on the second and fifth digits were, on average, 40% higher in female FU (n = 13) than in female OU (n = 10) and performance scores on the dexterity test were significantly higher for the left hand. The results of this study indicate that early signs of deterioration in hand function can be present in persons constantly exposed to computer tasks and that these signs are more readily apparent in women than in men. The loss of tactile spatial acuity found in female FU possibly reflect an early consequence of the degraded sensory representation of the hand resulting from constant repetitions of fine motor tasks.     

Protein supplement users among high school athletes have misconceptions about effectiveness

Protein supplements commonly are ingested by athletes to improve strength, agility, and speed. While athletes require a higher amount of protein (g.kg body weight) than nonathletes do to support protein synthesis, they do not necessarily need to consume protein from supplemental sources. To date, no studies have shown an advantage of ingesting protein supplements over natural, protein-containing foods; therefore, dietary sources of protein may be just as effective as protein supplemental sources in the regulation of muscle protein synthesis. Misconceptions regarding protein supplement effectiveness may originate from athletes' nutrition information sources. A survey questionnaire queried high school football players about sources of information and measured protein supplement misconceptions by using scores on a Protein Supplement Misconceptions Index. Sixty-one high school football players participated in the study; 39 were protein supplementers, and 22 were non-protein supplementers. There was a significant difference between index scores of protein supplementers and non-protein supplementers (t = -3.4, p = 0.001), indicating that protein supplementers had a greater level of misconceptions than non-protein supplementers did. Bonferroni post hoc procedures used with individual index items revealed that protein supplementers were more likely than non-protein supplementers to agree that "athletes should take protein supplements" (p = 0.001) and needed them "to gain as much muscle as possible" (p = 0.001). Greater misconceptions for protein supplementers may have resulted from the sources chosen for information and advice. Since coaches, parents, and friends were the primary sources of advice about protein supplements for protein supplementers, it would be valuable to provide nutrition education to these groups concurrently with educating young athletes to dispel ongoing misconceptions regarding the need for and effectiveness of protein supplements.     

Body composition and peak aerobic power in male international level Hungarian athletes

Body size, physique, body composition and physiological performance of elite athletes are independent aspects, have aroused the interest of exercise scientists, but studies that combine these aspects in elite athletes are scarcely available. The aim of the present study was to describe the selected anthropometric and exercise physiological characteristics of some Hungarian top athletes. The investigated subjects were qualified Hungarian water polo players (n=25), paddlers (n=24) and modem pentathlonists (n=20), all of whom had been medalists at several continental and intercontinental competitions. The athletes' body composition was estimated by the Drinkwater-Ross (45) body mass fractionation technique. Peak physiological performance was estimated by graded exhausting spiroergometric treadmill exercise. Intergroup differences in mean height, body mass and body composition characteristics were significant at the 5% level of random error. By the results of spiroergometry, all the three groups compared could be qualified as physically excellently trained. The greatest oxygen uptake relative to body mass was found in the modern pentathlonists (73.22 ml x kg(-1) x min(-1)) and the lowest one (59.79) in the water polo players. The authors do not disregard the favourable effects of regular and adequate trainings in the development of the studied characteristics, but in their opinion the process of proper selection has been the most important factor that explains the observed significant intergroup differences.